Field of the Invention
The present invention relates to an optical module provided with an optical multiplexer/demultiplexer that multiplexes or demultiplexes light and a method of manufacturing the same.
Background Art
Conventional optical modules align lenses at desired positions using a lens holder into which a lens is inserted and a holder guide, and fix members thereof through laser welding or the like. The material of the lens holder and the holder guide is stainless steel, steel, Kovar or the like (e.g., see Japanese Patent Application Laid-Open No. 2-139506). There is also a proposal of an optical module using a glass prism for an optical multiplexer/demultiplexer (e.g., see “Four-channel 25 Gbps Optical Receiver for 100 Gbps Ethernet (registered trademark) with Built-in Demultiplexer Optics” Optical Communication (ECOC), 2010 36th European Conference, Mitsubishi Electric Corporation, written by Aruga).
When fixing the lens holder and the holder guide through UV adhesion after alignment of lenses, the optical module described in Japanese Patent Application Laid-Open No. 2-139506 poses a problem that UV light is kicked by the metallic lens holder or holder guide and the lens position cannot be fixed.
Regarding the optical module described in “Four-channel 25 Gbps Optical Receiver for 100 Gbps Ethernet (registered trademark) with Built-in Demultiplexer Optics” Optical Communication (ECOC), 2010 36th European Conference, Mitsubishi Electric Corporation, written by Aruga, when the optical multiplexer/demultiplexer is held for alignment, the glass optical multiplexer/demultiplexer must not be damaged. For this reason, the optical multiplexer/demultiplexer needs to be held using, for example, a suctioning apparatus having a large area. Moreover, the optical multiplexer/demultiplexer is fixed to a pedestal using an adhesive. When an attempt is made to align the multiplexer/demultiplexer while keeping the multiplexer/demultiplexer in contact with the adhesive using the suctioning apparatus, the glass optical multiplexer/demultiplexer comes off the suctioning apparatus by yielding to the viscosity of the adhesive, making it difficult to make alignment at an appropriate position. Thus, after making alignment at a position at which the optical multiplexer/demultiplexer is caused to float from the adhesive, the optical multiplexer/demultiplexer is dismounted and caused to come into contact with the adhesive. Therefore, alignment is performed at a position different from the position where the optical multiplexer/demultiplexer should originally be fixed, and misalignment may occur when the optical multiplexer/demultiplexer is dismounted. This results in a problem that the optical multiplexer/demultiplexer cannot be fixed at an optimal position.